Go Back   DIY Chatroom Home Improvement Forum > Do It Yourself > Automotive Repairs

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 11-17-2013, 03:43 AM   #1
Newbie
 
Join Date: Nov 2013
Posts: 3
Rewards Points: 10
Default

99 Yukon Random Misfire


So just re did the top end and adjusted the valves twice, still getting codes for random misfire on cyl 6, repaved the injectors and started getting this problem has new plugs, wires abd cap n rotor and I'm stumped as to wat could be causing this problem any ideas would be appreciated

zach1926284 is offline   Reply With Quote
Old 11-17-2013, 04:29 AM   #2
Member
 
Join Date: Jul 2011
Location: pa
Posts: 255
Rewards Points: 250
Default

99 Yukon Random Misfire


Cracked porcelain on spark plug. Many yrs (1992) ago I had a 85 t bird w/ a 302v8. I changed plugs myself. Car would miss at low speeds. Dealer charged me $500( new egr valve etc) to fix. Still missed. Turned out to be a hairline crack on spark plug.

toolaholic is offline   Reply With Quote
Old 11-17-2013, 05:59 AM   #3
JOATMON
 
ddawg16's Avatar
 
Join Date: Aug 2011
Location: S. California
Posts: 7,487
Rewards Points: 2,316
Default

99 Yukon Random Misfire


...pull the fuel pump relay....

Crank the engine over for about 30 seconds..

Pull the plug....look at #6....does it have any moisture on it? If so...leaky head gasket.
__________________
"The dream is free but the hustle is sold separately."

My 2-Story Addition Build in Progress Link ... My Garage Build Link and My Jeep Build Link
ddawg16 is offline   Reply With Quote
Old 12-05-2013, 07:07 AM   #4
Member
 
Join Date: Dec 2011
Location: Michigan
Posts: 843
Rewards Points: 500
Default

99 Yukon Random Misfire


Did you use OEM AC Delco parts?
Hardway is offline   Reply With Quote
Old 12-05-2013, 10:54 AM   #5
Newbie
 
Join Date: Nov 2013
Posts: 3
Rewards Points: 10
Default

99 Yukon Random Misfire


Used felpro higher end gaskets, ac Delco plugs, ended up being one of the new injectors not sitting correctly and corrected itself, drove it last night after my wife had been driving for a few days and no longer misses at any rpm so that's honestly the only thing I can think of that could've been the problem, New design doesn't have the oem clips from 99, it was changed by gm in 00 or 01 according to service notes from gm global connect
zach1926284 is offline   Reply With Quote
Old 12-05-2013, 10:03 PM   #6
Member
 
ukrkoz's Avatar
 
Join Date: Dec 2010
Posts: 575
Rewards Points: 508
Default

99 Yukon Random Misfire


You can adjust valves on Yukon V8-s? Don't they have hydraulic lifters?
ukrkoz is offline   Reply With Quote
Old 12-09-2013, 05:39 PM   #7
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 6,610
Rewards Points: 2,502
Default

99 Yukon Random Misfire


Quote:
Originally Posted by ukrkoz View Post
You can adjust valves on Yukon V8-s? Don't they have hydraulic lifters?
+1

That is a bit scary to start with.
Windows on Wash is offline   Reply With Quote
Old 12-09-2013, 05:48 PM   #8
Newbie
 
Join Date: Nov 2013
Posts: 3
Rewards Points: 10
Default

99 Yukon Random Misfire


Not the lifters as its not a consistent misfire
zach1926284 is offline   Reply With Quote
Old 12-09-2013, 07:54 PM   #9
Member
 
ukrkoz's Avatar
 
Join Date: Dec 2010
Posts: 575
Rewards Points: 508
Default

99 Yukon Random Misfire


Zach, you missed my question. I have never heard of valve adjustments on GM V8s for those years, as they have hydraulic lifters. I was curious, how did you adjust the valves then. Your OP said so.

adjusted the valves twice
ukrkoz is offline   Reply With Quote
Old 12-10-2013, 06:41 AM   #10
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 6,610
Rewards Points: 2,502
Default

99 Yukon Random Misfire


+1

That was my point as well. Most GM Rocker assemblies are just bolt down until snug these days or spin the pushrod until you feel drag and 1/4 - 1/2 turn beyond there.

Windows on Wash is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
First Co. 36RCW5-HP blower stopping at random times cout HVAC 2 07-06-2011 04:51 PM
Random Orbital Sander Suggestions (<$100) hyunelan2 Tools 11 03-28-2011 07:49 AM
Outdoor post light - random blinking bulb handymike Electrical 9 06-14-2010 01:29 PM
Random GFCI tripping, Data Rack theatretch85 Electrical 5 07-10-2009 08:20 PM
Ridgid Random Orbit Sander jamiedolan Tools 2 03-17-2009 02:23 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.